Here are two traces of one of the first subjects ever tested with this procedure.
One trace is the average over all calm exposures. Note that the trace has three time components before the stimulus, during the stimulus and after the stimulus. The latency of the skin conductance response is between 2 and 3 second so you see a large response peak for the emotional and hardly any response for the calms.
Now what could be called presentiment is that just before the stimulus the subjects gets also a bit more aroused if the FUTURE stimulus is emotional. Note that with a proper randomization procedure the subject has no way to know what the future stimulus can be.
If we take many subjects and we average we get the signals in the following sheet/